22.2

java.io.DataOutput

THE PACKAGE JAVA.IO

22.2 The Interface

java.io.DataOutput

The

DataOutput

 interface provides for converting data from any of the Java prim 

itive types to a series of bytes and writing these bytes to a binary stream. There is

also a facility for converting a

String

 into Java modified UTF 8 format and writ 

ing the resulting series of bytes.

The

DataInput

 interface ( 22.1) can be used to read in and reconstruct Java

data from the binary output data produced by the

DataOutput

 interface.

The

DataOutput

 interface is implemented by classes

DataOutputStream

( 22.21) and

RandomAccessFile

 ( 22.23).

public interface DataOutput {

public void write(int b) throws IOException;

public void write(byte[] b)

throws IOException, NullPointerException;

public void write(byte[] b, int off, int len)

throws IOException, NullPointerException,

IndexOutOfBoundsException;

public void writeBoolean(boolean v) throws IOException;

public void writeByte(int v) throws IOException;

public void writeShort(int v) throws IOException;

public void writeChar(int v) throws IOException;

public void writeInt(int v) throws IOException;

public void writeLong(long v) throws IOException;

public void writeFloat(float v) throws IOException;

public void writeDouble(double v) throws IOException;

public void writeBytes(String s)

throws IOException, NullPointerException;

public void writeChars(String s)

throws IOException, NullPointerException;

public void writeUTF(String s)

throws IOException, NullPointerException;

}

For all the methods in this interface that write bytes, it is generally true that if

a byte cannot be written for any reason, an

IOException

 is thrown.

22.2.1

public void write(int b) throws IOException

The general contract for

write

 is that one byte is written to the output stream. The

byte to be written is the eight low order bits of the argument

b

. The 24 high order

bits of

b

 are ignored.

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